Bulky fabrics



April 23, 1957 A. cazs swsu.

BULKY FABRICS 2 Shoots-Shoot 1 Filed Nov. 14, 1955 Filling of polyacry/onifrile continuous-filament yarn 0f 0% to 3% prior having a residual shrinkage of 0% I039; prior Ia weaving Filling af pa/yacry/anitri/e caniinuaus-fiiameni yarn having a residual shrinkage of [5% la 30 prior to weaving INVENTOR. ARZ'HUI? ORESSWELL,

A TTORNE).

April 23, 1957 A. CRESSWELL 2,789,340

' BULKY FABRICS Filed Nov. 14, 1955 2 Sheds-Sheet 2 20 Bulky fabric material knitted from two parallel Po/yaory/on/tn/e 5 yarns yarn composed of twist d or untwisted ,2

cont nuous filaments /3 l8 and having a res/'dua/ shrinkage of /5% to 30% prior to knitting.

Po/yacrylonitrile yarn composed of twisted or untwisted cont/nuous filaments and having a residual shrinkage of 0 to prior to knitt/ng Bulky knitted fabric material Polyacry/onitrile I G 22 comprised of two different continuous-filament 24 Pv/yacry/vmtri/v yarns Wyyarn having a residual twisted together shrinkage of /5 to 30% prior to plytzwisting with yarn Po/yacry/onitrile continuous-filament yarn hawng a residual shrinkage 0f0% f0 3% prior to ply-twisting with arn 24 INVENTOR. AR THUR CRESSWEL L,

ATTORNEY.

BULKY FABRICS Arthur Cresswell, Stamford, Comm, assignor to American Cyanamid Company, New York, N. Y., a corporation of Maine Application November 14, 1955, Serial No. 546,807

7 Claims. (Cl. 28-76) This invention relates to the production of bulky fabrics and includes within the term bulky those fabrics having a crepe-like appearance or effect. The scope of the invention includes both method and article features.

It has been a recognized problem in the textile industry that yarns of different shrinkage may cause serious defects in the fabrics as, for example, tight ends in the warp of a Woven fabric and which results in so-called puckering. The present invention obviates this and other problems by a combination of high and low (or zero) shrinkage yarns of a particular kind to give controlled conditions that result in pleasing fabric elfects.

It is a primary object of the present invention to provide a new textile fabric which is characterized by being bulky either in its entirety or in particular areas thereof and which is comprised of a particular kind of synthetic continuous-filament yarn that imparts warmth, resilience, quick-drying properties, softness, and light weight to the fabric.

Another object of the invention is to provide a textile fabric that will increase the field of utility of polyacrylonitrile continuous-filment yarns.

Still another object of the invention is to provide a method by which the new textile fabrics described in the preceding paragraphs can be produced.

Other objects of the present invention will be apparent to those skilled in the art from the following more detailed description.

The foregoing objects and others are attained by producing a textile fabric comprised of a polyacrylonitrile continuous-filament yarn having a residual shrinkage of from to 3 prior to fabrication into said textile fabric and another polyacrylonitrile continuous-filament yarn having a residual shrinkage of from 15% to 30% prior to fabrication into said textile fabric. (By residual shrinkage" as used herein and in the appended claims is meant the linear contraction that occurs when the multifilament thread is allowed to relax without tension in boiling water at 100 C.) These different polyacrylonitrile continuousfilament yarns are conjointly fabricated (e. g., by knitting, weaving, etc.), after which the fabric is subjected to treatment with a hot, fluid medium, for instance, air, water, steam, molten metal (e. g., Woods metal), high-boiling alcohols such as propyl, butyl and amyl alcohols, ethylene glycol, diethylene glyco, gycero, etc., acohol-ethers, e. g., ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, etc., hydrocarbon oils such as mineral oils, etc., and other hot, fluid media. The fluid medium may be heated by any suitable means, for instance, air heated by radiant heat may constitute the hot, fluid medium with which the fabric is contacted. The temperature of the hot, fluid medium should be at least 99 C. but below the decomposition temperature of the aforesaid polyacrylonitrile yarns. This temperature generally is from about 99 C. to about 200 C., and preferably within the range of from 99 C. to 110 or 120 C.

The treatment of the fabric with the hot, fluid medium either may be an independent step to which the fabric nited States Patent 0 F "ice is subjected or it may be carried out in conjunction with other steps employed in processing a fabric, for example, a dyeing operation or tensionless tentering. If the hot, fluid medium is a hot, volatile liquid the treated fabric material is then dried. The described treatment imparts to the fabric a bulky appearance, which may be crepelike if the yarns have been individually twisted and plytwisted.

The shrinkable and outshrunk (0% to 3% residual shrinkage) yarns may be wound together without individual twist and subsequently twisted as a composite; or, each yarn may be individually twisted and then knit or woven together as two parallel yarns; or, as still another variation, each yarn may be individually twisted and plied together for weaving or knitting.

When the diiferent polyacrylonitrile continuous-filament yarns are ply-twisted together, the degree of twist may be varied as desired or as conditions may require. For instance, in certain cases it may be desirable that the yarns be twisted together with a low twist of the order of one to two turns per inch. In other cases it may be ad- ,vantageous to ply-twist the different yarns together with a higher twist as, for example, ten to twenty turns per inch, this latter condition leading to a somewhat more crepe-like fabric.

Unusual effects in fabric appearance can be attained by plying in one case, for example, unretracted yarn composed of an acrylonitrile ternary basic polymer of the type shown in Example 1 (which follows) together with a retracted yarn composed of a non-basic acrylonitrile polymer of the type shown in Example 4 (which follows). Such a composite thread, when fabricated into a woven or knit construction and dyed with, for example, an acid dyestufi, produces unusual and pleasing effects both from color and design aspects; This is a matter of considerable practical and commercial importance, since it increases the field of utility of polyacrylonitrile continuous-filament yarns.

In order that those skilled in the art may better understand how the present invention can be carried into effect, the following examples are given by way of illustration and not by way of limitation. All percentages are by weight.

Example 1 A 10% solution of a ternary polymer comprised of about 6.2% Z-methyI-S-Vinylpyridine, about 5.8% vinyl acetate and about 88.0% acrylonitrile dissolved in a 48% aqueous sodium thiocyanate solution is extruded through a 45-hole spinnerette with -micron holes into a coagulating bath of 10% aqueous sodium thiocyanate solution at 1 C. The multifilament gel yarn that forms on coagulation of the extruded solution is washed free of sodium thiocyanate and then stretched 8.5 times in water at 98 C. The stretched thread is then continuously dried on convergent, electrically-heated rolls.

For a period the yarn prepared as described above is collected on a ring-twisting bobbin with about 1.85 turns per inch 8 twist. Following the preparation of this unretracted (unshrunken) yarn, the yarn, as delivered from the drying rolls, is led through a horizontal retraction furnace in which the air temperature is maintained at 400 C. and wherein the yarn is allowed to retract e easao 3 yarn and 2.6% in the case of the yarn which has been retracted Three plied yarns, described hereinafter, are prepared from the above two yarns, using a ply twist of about 10.2 turns per inch Z twist:

a. One thread of unretracted yarn and one thread of retracted yarn.

b. Two threads of unretracted yarn.

0. Two threads of retracted yarn.

Each of these plied yarns is then circular knit to form tubing. Each tube is dyed at the boil with an acid dye for a period of 30 minutes, then is washed with mildly warm water and allowed to dry. After drying, the above three knit tubes appear as follows:

a. Fabric has shrunk from original width and is bulky.

b. Fabric has shrunk from original width and is not bulky, but tight.

0. Fabric has not appreciably shrunk and is not bulky.

Example 2 Circular knitting is carried out with two parallel threads, one of unretracted (17.8% residual shrinkage) and one of retracted (2.6% residual shrinkage) prepared as described in Example 1. After dyeing at the boil, washing and drying, the circular knit tubing is found to have shrunk and to be slightly more bulky than the outshrunk tube as made from the plied yarn of Example 111.

Example 3 One thread of a homopolymeric acrylonitrile continuous-filament yarn having a residual shrinkage in boiling water of is plied with another thread of the same composition but which has no residual shrinkage in boiling water. These plied yarns are used both as warp and as filling yarn in a woven construction. Subsequent to de-sizing and either prior to or during dyeing, the woven fabric is allowed to relax and shrink in either boiling water alone or in an aqueous solution containing a dye or other eiiect agent, thereby acquiring a bulky appearance in contra-distinction to that of a fabric similarly woven from two plied polyacrylonitrile threads, both of which have no residual shrinkage in boiling water.

Example 4 A spinning dope, comprised of a copolymer of about 5% methyl acrylate and about 95% acrylonitrile dissolved in a concentrated aqueous solution of sodium thiocyanate, is extruded through a spinnerette in accordance with Cresswell U. S. Patent No. 2,558,730, dated July 3, 1951, to form a 45-filarnent yarn, equivalent to 75-denier when retracted. The threads are washed, stretched and dried by using spinning machines of the type disclosed in Cresswell et a1. U. S. Patent No. 2,558,733, dated July 3, 1951. Threads from one machine are passed through retraction furnaces to permit 15% retraction, while threads from the other machine are collected without retracting through the furnaces. Threads from each machine are collected by fiat winding in an untwisted condition.

An untwisted thread that has been retracted and an untwisted thread that has not been retracted are brought together as parallel yarns, which are then twisted to about one turn per inch. This composite yarn is circular knit to form a tubing. after which it is dyed with an acetate dyestuif at the boil with permitted shrinkage. The fabric is then washed with mildly warm water and allowed to dry in a loop dryer. The resulting fabric is bulky and very attractive from an aesthetic standpoint.

It will be understood, of course, by those skilled in the art that my invention is not limited to the use of only those polyacrylonitrile continuous-filament yarns produced in the particular way and having the particular composition and physical characteristics given by way of illustration in the foregoing examples; nor to the par- 4 ticular methods by which such yarns are fabricated into bulky fabrics that are described in the aforesaid examples. Thus, instead of being produced by the particular wetspinning methods described in the examples, they may be made by any of the other known wet-spinning methods or by any of the known dry-spinning methods.

The acrylonitrile polymers from which the polyacrylonitrile continuous-filament yarns used in practicing the present invention are made include fiber-forming (fibert'orinable) homopolymeric acrylonitrile and fiber-forming (fiber-formable) acrylonitrile copolymers (thermoplastic acrylonitrile copolymers) containing in the polymer molecules an average of, for example, at least about 40%, preferably at least about by weight of combined acrylonitrile. Taking as an example the expression an acrylonitrile polymer containing in the polymer molecules an average of at least about 40% by weight of combined acrylonitrile, this means herein a polymerization product (homopolymer, copolymer or graft polymer or mixtures thereof) containing in the molecules thereof an average of at least about 40% by weight of the acrylonitrile unit, which is considered to be present in the individual polymer molecule as the group or, otherwise stated, at least about 40% by weight of the reactant substance converted into and forming the polymerization product is acrylonitrile. The expression an acrylonitrile polymer containing in the polymer molecules an average of at least about 75% by weight of combined acrylonitrile has a similar meaning herein.

Illustrative examples of monomers which may be ccpolymerized with acrylonitrile to yield a polymerization product containing in the polymer molecules an average of at least about 40%, preferably at least about 75 by weight of combined acrylonitrile are compounds containing a single CHz=C grouping, for instance, the vinyl esters and especially the vinyl esters of saturated aliphatic monocarboxylic acids, e. g., vinyl acetate, vinyl propionate, vinyl butyrate, etc.; vinyl and vinylidene halides, e. g., the vinyl and vinylidene chlorides, bromides and fluorides; allyl-type alcohols, e. g., allyl alcohol, methallyl alcohol, vethallyl alcohol, etc.; allyl, methallyl and other unsaturated monohydric alcohol esters of monobasic acids, e. g., allyl and methally-l acetates, laurates, cyanides, etc.; acrylic and alkacrylic acids (e. g., methacrylic, ethacrylic, etc.) and esters and amides of such acids (e. g., methyl, ethyl, propyl, butyl, etc., acrylates and methacrylates, acrylamide, methacrylamide, N- methyl, -ethyl, -propyl, -butyl, etc., acrylamides and methacrylamides, etc); methacrylonitrile, ethacrylonitrile and other hydrocarbon-substituted acrylonitriles; unsaturated aliphatic hydrocarbons containing a single Hz=C grouping, e. g., isobutylene, etc.; and numerous other vinyl, acrylic and other compounds containing a single CH2=C grouping which are copolymerizable With acrylonitrile to yield thermoplastic copolymers. Alkyl esters of alpha, beta-unsaturated polycarboxylic acids also may be copolymerized with aerylonitrile to form copolymers, e. g., the dimethyl, -ethyl, propyl, -butyl, etc., ester of maleic, fumaric, citraconic, etc., acids.

Ordinarily, the molecular weight (average molecular weight) of the homopolymeric or copolymeric acrylonitrile, from which the polyacrylonitrile continuous-filament yarns used in practicing the present invention are made, is within the range of 25,000 or 30,000 to 200,000 or 300,000 or higher, and advantageously is of the order of 50,000 to 100,000, e. g., about 70,00080,000, as calculated from a viscosity measurement of the said polymerization product in dimethyl formamide using the Staudinger equation (reference: Houtz U. S. Patent No. 2,404,713, dated July 23, 1946).

The bulky (including crepy or crepe-like) textile fabtics of this invention can be made, for instance, in the form of woven fabrics for manufacturing dresses, etc., that is, so-called dress fabrics; or in the form of bulky knit wear, such as light-knit fabrics for lingerie, sleeping apparel, etc.

In the accompanying drawing, which is illustrative of several embodiments of the invention, Figs. 1 and 2 are, respectively, a perspective, side view and a sectional view (both views on an enlarged scale) of a portion of a bulky, woven, fabric material embodying the invention; Figs. 3 and 4 are, respectively, a side view and a sectional view taken along the line 44 of Fig. 3 (both views on an enlarged scale) of a portion of a bulky, fabric material knitted from two parallel polyacrylonitrile yarns composed of twisted or untwisted continuous filaments; and Figs. 5 and 6 are, respectively, a side view and a sectional view taken along the line 6-6 of Fig. 5 (both views on an enlarged scale) of a portion of a bulky, knitted, fabric material comprised of two, different polyacrylonitrile, continuous-filament yarns ply-twisted together.

With further reference to the drawing, and more particularly to Figs. 1 and 2 thereof, the numeral 10 designates a warp of polyacrylonitrile continuous-filament yarn having a residual shrinkage of 0% to 3% prior to weaving; 12 designates a filling of polyacrylonitrile continuousfilament yarn having a residual shrinkage of 0% to 3% prior to weaving; and 14 designates a filling of polyacrylonitrile continuous-filament yarn having a residual shrinkage of 15% to 30% prior to weaving.

In Figs. 3 and 4, the numeral 16 designate generally a bulky, knitted, fabric material embodying the invention and which is knitted from two, parallel, polyacrylonitrile yarns composed of twisted or untwisted continuous filaments. The numeral 18 designates a polyacrylonitrile yarn composed of twisted or untwisted continuous filament and having a residual shrinkage of 15 to 30% prior to knitting; and 20 designates a polyacrylontrile yarn composed of twisted or untwisted continuous filaments and having a residual shrinkage of 0% to 3% prior to knitting.

In Figs. 5 and 6, the numeral 22 designates generally a bulky, knitty, fabric material embodying the invention and which is comprised of two, different polyacrylonitrile yarns ply-twisted together. The numeral 24 designates a polyacrylonitrile continuous-filament yarn having a residual shrinkage of 15 to 30% prior to ply-twisting with yarn 26, which latter designates a polyacrylonitrile continuous filament yarn having a residual shrinkage of 0% to 3% prior to ply-twisting with yarn 24.

I claim:

1. A textile fabric comprised of a polyacrylonitrile continuous-filament yarn having a residual shrinkage of from 0% to 3% prior to fabrication into said textile fabric and another polyacrylonitrile continuous-filament yarn having a residual shrinkage of from 15% to 30% prior to fabrication into said textile fabric, said different polyacrylonitrile continuous-filament yarns being conjointly fabricated and the areas of the said fabric containing the same being bulky due to the differential shrinkage between the said yarns upon treatment of the said textile fabric with a hot, fluid medium.

2. A bulky fabric material woven from two different polyacrylonitrile continuous-filament yarns, one of which has a residual shrinkage of from 0% to 3% prior to fabrication into said fabric material and the other of which has a residual shrinkage of from 15% to 30% prior to fabrication into said fabric material, the bulky effect imparted to said fabric material being due to the diflerential shrinkage between the said yarns upon treatment of the said fabric material with a hot, fluid medium.

3. A bulky, knitted fabric material comprised of two different polyacrylonitrile continuous-filament yarns which have been ply-twisted together, one of said yarns having a residual shrinkage of from 0% to 3% and the other having a residual shrinkage of from 15 to 30% prior to being ply-twisted together, the bulky efiect imparted to said fabric material being due to the differential shrinkage between the said yarns upon treatment of the said fabric material with a hot, fluid medium.

4. A bulky fabric material knitted from two parallel yarns each of which is composed of untwisted continuous filaments, one of said yarns being a polyacrylonitrile continuous-filament yarn having a residual shrinkage of from 0% to 3% prior to knitting and the other being a polyacrylonitrile continuous-filament yarn having a residual shrinkage of from 15% to 30% prior to knitting, the bulky efiect imparted to said fabric material being due to the difierential shrinkage between the said yarns upon treatment of the said fabric material with a hot, fluid medium.

5. A bulky fabric material knitted from two parallel yarns each of which is composed of twisted continuous filaments, one of said yarns being a polyacrylonitrile continuous-filament yarn having a residual shrinkage of from 0% to 3% prior to knitting and the other being a polyacrylonitrile continuous-filament yarn having a residual shrinkage of from 15% to 30% prior to knitting, the bulky effect imparted to said fabric material being due to the differential shrinkage between the said yarns upon treatment of the said fabric material with a hot, fluid medium.

6. The process of producing a textile fabric containing bulky areas which comprises conjointly fabricating into a fabric a polyacrylonitrile continuous-filament yarn having a residual shrinkage of from 0% to 3% prior to fabrication into said fabric and another polyacrylonitrile continuous-filament yarn having a residual shrinkage of from 15% to 30% prior to fabrication into said fabric, and subjecting the resulting fabric to treatment with a hot, fluid medium at a temperature of at least 99 C. but below the decomposition temperature of the aforesaid polyacrylonitrile yarns, thereby to impart bulkiness to areas of the said fabric containing the conjointly fabricated yarns due to the differential shrinkage between the said yarns.

7. A process as in claim 6 wherein the hot, fluid medium is at a temperature of from 99 C. to 200 C.

References Cited in the file of this patent New York 16, New York. Copyright 1952. Pages 220- 221. Copy in Div. 21.

Dupont Textile Fibers Technical Information; Bulletin Oil-67; August 1955. Copy in Div. 21.

Introduction of Textile Chemistry by Bruce E. Hartsuch; John Wiley and Sons, Inc., New York, New York, page 343. Copyright 1950. 

1. A TEXTILE FABRIC COMPRISES OF A POLYACRYLONITRILE CONTINUOUS-FILAMENT YARN HAVING A RESIDUAL SHRINKAGE OF FROM 0% TO 3% PRIOR TO FABRICATION INTO SAID TEXTILE FABRIC AND ANOTHER POLYACRYLONITRILE CONTINUOUS-FILAMENT YARN HAVING A RESIDUAL SHRINKAGE OF FROM 15% TO 30% PRIOR TO FABRICATION INTO SAID TEXTILE FABRIC, SAID DIFFERENT POLYACRYLONITRILE CONTINUOUS-FILAMENT YARNS BEING CONJOINTLY FABRICATED AND THE AREAS OF THE SAID FABRIC CONTAINING THE SAME BEING BULKY DUE TO THE DIFFERE NTIAL SHRINKAGE BETWEEN THE SAID YARNS UPON TREATMENT OF THE SAID TEXTILE FABRIC WITH A HOT, FLUID MEDIUM. 